A method of surface treatments using an electrode facing a base material for plasma generation almost cylindrical in shape and rotating it at a high speed rotation was developed recently as a means of forming a film or the like by using chemical reaction (Japanese Unexamined Patent Publication No. 9-104985, p. 7 to 8, FIGS. 1 and 2).
The equipment described in the application is an equipment in which the surface-treating gas is dragged into the space between a rotary electrode and a base material by rotation of the rotary electrode where plasma is generated, while a base material is conveyed, the rotary electrode is rotated, and a radio/high frequency power (or DC power) is applied to the rotary electrode; and it is possible to form a thin film on the surface of the base material by conveying the base material therein while the plasma is generated.
The equipment is useful as a means of performing surface treatment under atmospheric pressure or a pressure close to it, but it is very difficult to control the clearance of the narrow gap between the base material and the rotary electrode, and thus, slight vibration of the base material on conveyor belt or bend of the base material by heat may impair favorable treatment.
The remote plasma CVD described in Japanese unexamined patent publication No. 2002-237480, p. 7 to 8, FIG. 3) would be a possible means of eliminating such strict dimensional control. According to the method, a film is deposited on the surface of a base material by forming a solid dielectric substance on at least one opposing face of opponent electrodes facing each other, generating discharge plasma while supplying a surface-treating gas in under a pressure close to atmospheric pressure and applying a pulsed electric field between the electrodes, and inducing the plasma into contact with the surface of the base material placed outside the discharge space.